In general, a DM technique is a technique that when a particular processing command is received from a DM server, a DM client performs the corresponding command.
In the DM technique, a certain device (e.g., terminal) makes a state value changing while an operation is being performed or a periodically (or when an event occurs) measured value DM object of a DM tree and stores a corresponding value in the DM object whenever the values change. Accordingly, the DM server remotely reads and checks the state value or the measured value stored in the DM object through the DM technique.
However, a state value or a measured value may be lost as it is updated with a new value unless it is not immediately read, so the server should perform a procedure for opening a DM session and reading corresponding values each time.
Thus, in case of a very frequently updated state value or measured value or in case of very quickly responding to a changed state, the server is to very frequently open the DM session, which disadvantageously causes an excessive network load and operation costs. In addition, when it is not possible to connect the DM server and a device, for example, when the device is in a shadow area in a wireless environment, the server cannot read the corresponding values. In this case, logging is necessary to read the corresponding state value or the measured value at a time point when an event occurs or periodically and store it in a region so that the server can read it later.